Where corrugated cardboard sheets for corrugated boxes are printed one-by-one, an area of the corrugated cardboard sheet to be printed is a portion of the surface of the corrugated cardboard sheet corresponding to four face sides of the box to be formed from the sheet. On the planar cardboard sheet to be printed, the four face sides have an overall rectangular shape.
As shown in an elevation view in FIG. 1, a printer system 1 for a corrugated cardboard sheet 5, includes a feeder 10 having a kicker 11 for feeding the sheets 5, one or more printer stages 20, a creaser or slitter 30, a slotter 40, and a stacker (not shown), disposed in sequence along the direction of travel of the sheet 5 to be printed. The direction of travel of the cardboard sheet from the feeder 10 through the remainder of the printer system 1 is from right to left as shown by the broad arrow. Each of the printer stages includes a pair of rollers, 22a and 22b, where one of the rollers 22b has a printing die 23 (shown in FIG. 2) on the peripheral surface thereof. The second of the rollers 22a acts as a pressure roller in the printing process. The corrugated cardboard sheet 5, shown in plan view, is passed between the rollers 22a and 22b of each of the stages of the printer, where the rollers 22a and 22b are sized and dimensioned so that a predetermined nip pressure causes the corrugated cardboard sheet 5 sheet to be propelled in the direction of feed. At the time of passage between the rollers 22a and 22b, one surface of the corrugated cardboard sheet 5 is printed by contacting the corrugated cardboard sheet 5 with the printing die 23. Thus the pair of rollers 22a and 22b serve both to transport the sheet from stage-to-stage of the printer 1 and to print the image on the sheet with the printing die 23 affixed to the periphery of the roller 22b. 
Each of the colors which may be required in the printing process is applied by a separate printer stage 20, the printer stages being disposed along the direction of feed of the sheet 5. Examples of printing on the sheet 5 are shown in FIG. 1, each example representing the state of the sheet 5 after completion of the printing process represented by the stage 20 of the printer 1 disposed adjacent thereto.
FIG. 2a shows the relationship of a corrugated cardboard sheet 5 (or “sheet”) to the printing cylinder of a stage 20 of the printer 1. A printing area 6, shown as a lined region of the sheet 5, represents that area of the surface of the sheet 5 where printing may be performed. The width of the area to be printed corresponds to the width W of the printing die 23. The longer dimension X of the sheet 5 may be termed the “longitudinal” dimension, and the shorter dimension Y of the sheet 5 may be termed the “transverse” dimension. In the example of FIG. 1, the sheet is being fed through the printer 1 in the transverse direction; that is, the transverse dimension of the sheet is oriented in the direction of travel of the sheet 5 through the printer 1. An edge of the sheet 5 is also shown where the corrugations may be seen to have an approximately sinusoidal shape having an upper and lower surface adhered thereto. As shown, the direction of corrugation is along the transverse direction of the sheet 5, such that the sinusoidal form extends in the longitudinal direction.
The length of the print area 6 determines the circumferential length of the print die 23 on the periphery of the printing cylinder 22b. The linear length along the direction of travel of the sheet 5 which can be printed by the printing die 23 depends on the diameter D of the cylinder 22b and the angular extent θ of the periphery occupied by the printing die 23. For a fixed angular extent θ, the diameter D of the print cylinder 22b depends linearly on the longitudinal dimension X of the sheet 5. As the size of the sheet 5 increases, the diameter of the printing cylinder 22b increases accordingly, and the overall dimensions of the printer 1 may be come quite large, and is determined by the longitudinal dimension of the largest sheet that the printer is intended to accommodate.
The corrugated cardboard sheet 5 may also be fed so that the longitudinal dimension X is perpendicular to the direction of feed, as shown in FIG. 1. This arrangement results in increasing the width of the printer 1 in accordance with the maximum longitudinal dimension X of sheets 5 to be accommodated by the printer 1. FIG. 1 shows a situation where an area on the corrugated cardboard sheet 5, corresponding to a faces of the completed box 50, are separately printed with a different color, and the color is represented by a differing symbol (circle, triangle, square and star). Of course each of the faces may be printed with all of the colors and the example is merely for clarity. However, particularly in the situation which obtains when there is a face on which not all of the colors are printed on each box face portion of the corrugated cardboard sheet 5, the orientation of the corrugated cardboard sheet 5 with respect to the direction of feed may be altered, resulting in a lack of registration of the images or colors.